• The first roads were invented in the Bronze Age in 4000 BCE, created by the older Indus Valley Civilization. This was the first time that straight, 90 degree intersecting roads were seen.
• The Roman civilization created advanced road systems that encouraged travel and connection, forming a lifeline of connecting various cultures, institutions and beliefs.
• The Romans managed to create major roadways and highways with traffic segregation, something unheard of before.
• They had 372 roads with 29 major highways. The first major roadway was called the Appian Way, connecting Rome with Capua, back in 312 BCE. This road was used efficiently during the Samnite Wars in the same era.

• Rome was founded in 753 BCE by Romulus, the first king, and the son of Mars, the God Of War.
• Rome knew three eras: The Period of Kings from 625 to 510 BCE, Republican Rome from 510 to 31 BCE and Imperial Rome from 31 BCE to 476 CE.
• The Roman empire consisted of Spain, Portugal, France, Belgium, England, Wales, parts of Germany, and many territories in Central Europe and Africa.

The Acropolis is a distinctive feature of today's Athens that was built in the 5th century BCE. It is a cluster of buildings on a rocky outcrop. The famous Parthenon temple on the Acropolis was built to honor Athena and to serve the city's treasury.

Athens during the 5th century BCE was lively. The heart of Athens was its marketplace, or Agora (a place where people gather.) The structures surrounding the Agora's market stalls included stone benches, various altars, and temples, a building named the Aiakeion where laws and legal decisions were displayed, and various stoas or covered porticos.

Athens was an unusually open society. It was open to foreign goods, foreigners that were able to attain high-status roles, and the exchange of strange ideas.

Athens borrowed many ideas, such as the Phoenician alphabet, Egyptian medicine and sculpture techniques, Babylonia mathematics, and Sumerian literature, and then improved upon it.

Humanity has been vulnerable to rapidly spread illnesses because disease propagates more easily in concentrated populations without adequate sanitation.

Advances in sanitation have allowed people to live near one another in cities with less risk to their health, in particular, safe disposal of effluent to spare the water supply from contamination.

The Indus Valley civilization arose in the floodplains of the Indus and Sarasvati rivers around 5000 years ago.

In the largest structure in the city Mohenjo-Dar was an immense, elevated public bathhouse, measuring almost 900 square feet. The status of the bathhouse as the city's largest structure suggests that the people highly valued cleanliness.